The present invention relates to a magnetic disk drive and a method for fabricating the same, in which a cover seal for covering a seam between an opening edge of a base and a cover for closing the opening edge of the base is improved.
A magnetic disk drive is principally constituted of a head disk assembly (hereinafter abbreviated as “an HDA” in the specification). The HDA is configured such that a magnetic disk, an actuator head suspension assembly, a spindle motor and electronic parts are tightly enclosed in a clean ambient environment by the use of a base for containing therein the magnetic disk, the actuator head suspension assembly, the spindle motor and the electronic parts, a cover for covering an opening of the base, and a cover seal for covering a seam between an opening edge of the base and the cover. Therefore, the magnetic disk drive is assembled in a clean room. As the actuator head suspension assembly in the magnetic disk drive is connected to an actuator for supporting a head for reading and writing data from and in a rotating magnetic disk and locating the head at a predetermined position. A mechanism for driving the actuator is a voice coil motor (hereinafter abbreviated as “a VCM” in the specification) including a coil, a magnet and a yoke.
There have been various kinds of conventionally proposed cover seals for use in holding air-tightness in the above-described magnetic disk drive.
For example, Patent Document 1 (Japanese Patent Laid-open No. 10-55662 (pages 2 and 3 and FIGS. 1 and 2)) discloses the technique in which a cover member such as a pressing lid is disposed in a box-shaped base member containing a magnetic disk mechanism therein, and the inside of a magnetic disk drive is tightly enclosed by covering a clearance defined at a joint between the base member and the cover member with a seal member (i.e., a cover seal) from above. The seal member is constituted by laminating an aluminum layer on an adhesive layer or laminating an aluminum layer, an adhesive layer and a polyethylene terephthalate layer in this order on an adhesive layer.
Patent Document 2 (Japanese Patent Laid-open No. 11-232833 (pages 3 and 4 and FIGS. 2 to 5), for example, discloses the technique in which a housing opening formed at a housing body (i.e., a base) containing therein a magnetic disk, a magnetic head and the like is covered with a flat cover, before a seam between a housing opening edge and a cover is adhesively sealed with a cover seal at the upper surface of the cover in an air-tight manner. The cover seal is constituted by laminating a metallic foil layer on an adhesive layer or laminating a polyethylene terephthalate layer, an adhesive layer and another polyethylene terephthalate layer in this order on another adhesive layer.
Patent Document 3 (Japanese Patent Laid-open No. 2002-322444 (pages 2 and 3 and FIG. 1), for example, discloses the technique in which an adhesive label for an HDD (i.e., a cover seal) is bonded to an outer surface of a top cover of a hard disk drive constituted of a box-shaped housing body (i.e., a base) containing therein a recording disk, a magnetic head, a spindle motor and the like, and a top cover corresponding to the housing body, thereby holding air-tightness of the hard disk drive. In the adhesive label for an HDD, an adhesive agent layer is formed at either surface of a laminate base member consisting of at least three layers, that is, a metallic foil layer and resin film layers laminated at both surfaces of the metallic foil layer.
Alternatively, Patent Document 4 (Japanese Patent Laid-open No. 2001-216774 (pages 2 to 4 and FIGS. 2 to 4), for example, discloses the technique of holding air-tightness of a housing, in which a seat member made of rubber or a synthetic resin is disposed at a joint between a case body (i.e., a base) containing therein a disk, a magnetic head, a spindle motor and the like and a lid for covering an opening formed at the case body. The seat member is formed by laminating a seat body, an adhesive agent and a cover film in this order. The seat body is bonded to the lid. The cover film is peeled off in such a manner as to expose the adhesive agent at a portion facing to an end surface on a side wall of the case body, thereby holding the air-tightness of the housing.